set a max on input html code example

Example 1: input maxlength

<form action="/action_page.php">
  <label for="username">Username:</label>
  <input type="text" id="username" name="username" maxlength="10"><br><br>
  <input type="submit" value="Submit">
</form>

Example 2: input max length

<input maxlength="10" />